<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%--
  Created by IntelliJ IDEA.
  User: zhangyiyi
  Date: 2025/3/3
  Time: 9:46
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<!--判断用户是否登录-->
<c:if var="isLogin" test="${empty param.username}">
    <form>
        <input name="username" type="text"/>
        <input type="submit">
    </form>
</c:if>
<c:if test="${!isLogin}">
    ${param.username}，登录成功
</c:if>
</body>
</html>
